This incredibly fast 400mm lens abounds in special-and unique-features. Because of a special cam focusing system, not only is the lens shorter, smaller in diameter and lighter in weight, but it focuses "faster" at close distances and "slower" at longer distances, for improved handling.
And because the focusing is internal, the lens stays the same length even at close focuing distances. Naturally, its optical quality is strickly professional-caliber all the way, and for the serious photographer who needs length, speed and sharpness, there is no finer lens.
Type: super telephoto
Construction: 6 elements in 5 groups
Angle of view: 6 degrees 10 minutes
Minimum Aperture: F/22
Closest Focusing Distance: 13ft
Filter size: 34 drop-in with holder
Length: 11 1/8 in
Weight: 2lbs 14oz.